Petr Mladek 5b66867966 watchdog: fix barriers when printing backtraces from all CPUs ...

[ Upstream commit 9f113bf760 ]

Any parallel softlockup reports are skipped when one CPU is already
printing backtraces from all CPUs.

The exclusive rights are synchronized using one bit in
soft_lockup_nmi_warn.  There is also one memory barrier that does not make
much sense.

Use two barriers on the right location to prevent mixing two reports.

[pmladek@suse.com: use bit lock operations to prevent multiple soft-lockup reports]
  Link: https://lkml.kernel.org/r/YFSVsLGVWMXTvlbk@alley

Link: https://lkml.kernel.org/r/20210311122130.6788-6-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2021-05-19 10:13:00 +02:00

..

bpf

bpf: Prevent writable memory-mapping of read-only ringbuf pages

2021-05-14 09:50:46 +02:00

cgroup

cgroup-v1: add disabled controller check in cgroup1_parse_param()

2021-02-17 11:02:25 +01:00

configs

…

debug

kgdb: fix to kill breakpoints on initmem after boot

2021-03-04 11:38:46 +01:00

dma

swiotlb: respect min_align_mask

2021-05-07 11:04:32 +02:00

entry

x86/entry: Move nmi entry/exit into common code

2021-03-17 17:06:36 +01:00

events

perf: Rework perf_event_exit_event()

2021-05-11 14:47:31 +02:00

gcov

gcov: re-fix clang-11+ support

2021-04-14 08:41:58 +02:00

irq

genirq/matrix: Prevent allocation counter corruption

2021-05-11 14:47:17 +02:00

kcsan

kcsan, debugfs: Move debugfs file creation out of early init

2021-05-11 14:47:33 +02:00

livepatch

kernel/: fix repeated words in comments

2020-10-16 11:11:19 -07:00

locking

locking/qrwlock: Fix ordering in queued_write_lock_slowpath()

2021-04-28 13:40:00 +02:00

power

PM: EM: postpone creating the debugfs dir till fs_initcall

2021-03-30 14:32:04 +02:00

printk

printk: fix deadlock when kernel panic

2021-03-04 11:38:41 +01:00

rcu

rcu: Remove spurious instrumentation_end() in rcu_nmi_enter()

2021-05-14 09:50:22 +02:00

sched

smp: Fix smp_call_function_single_async prototype

2021-05-14 09:50:46 +02:00

time

posix-timers: Preserve return value in clock_adjtime32()

2021-05-11 14:47:16 +02:00

trace

tracing: Restructure trace_clock_global() to never block

2021-05-11 14:47:40 +02:00

.gitignore

kbuild: update config_data.gz only when the content of .config is changed

2021-05-11 14:47:37 +02:00

acct.c

kernel: acct.c: fix some kernel-doc nits

2020-10-16 11:11:19 -07:00

async.c

…

audit_fsnotify.c

fsnotify: generalize handle_inode_event()

2020-12-30 11:54:18 +01:00

audit_tree.c

fsnotify: generalize handle_inode_event()

2020-12-30 11:54:18 +01:00

audit_watch.c

fsnotify: generalize handle_inode_event()

2020-12-30 11:54:18 +01:00

audit.c

audit: Remove redundant null check

2020-08-26 09:10:39 -04:00

audit.h

…

auditfilter.c

…

auditsc.c

…

backtracetest.c

…

bounds.c

…

capability.c

LSM: Signal to SafeSetID when setting group IDs

2020-10-13 09:17:34 -07:00

compat.c

…

configs.c

…

context_tracking.c

…

cpu_pm.c

notifier: Fix broken error handling pattern

2020-09-01 09:58:03 +02:00

cpu.c

kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling

2020-11-27 00:10:39 +11:00

crash_core.c

…

crash_dump.c

…

cred.c

…

delayacct.c

…

dma.c

…

exec_domain.c

…

exit.c

kernel/io_uring: cancel io_uring before task works

2021-01-30 13:55:18 +01:00

extable.c

…

fail_function.c

fail_function: Remove a redundant mutex unlock

2020-11-19 11:58:16 -08:00

fork.c

mm/fork: clear PASID for new mm

2021-03-30 14:31:52 +02:00

freezer.c

Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"

2021-04-07 15:00:14 +02:00

futex.c

futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI

2021-05-11 14:47:37 +02:00

gen_kheaders.sh

…

groups.c

LSM: Signal to SafeSetID when setting group IDs

2020-10-13 09:17:34 -07:00

hung_task.c

kernel/hung_task.c: make type annotations consistent

2020-11-02 12:14:19 -08:00

iomem.c

…

irq_work.c

…

jump_label.c

static_call: Fix static_call_update() sanity check

2021-03-25 09:04:18 +01:00

kallsyms.c

treewide: Convert macro and uses of __section(foo) to __section("foo")

2020-10-25 14:51:49 -07:00

kcmp.c

exec: Transform exec_update_mutex into a rw_semaphore

2021-01-09 13:46:24 +01:00

Kconfig.freezer

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Kconfig.hz

…

Kconfig.locks

…

Kconfig.preempt

…

kcov.c

…

kexec_core.c

kernel: kexec: remove the lock operation of system_transition_mutex

2021-02-03 23:28:37 +01:00

kexec_elf.c

…

kexec_file.c

ima: Free IMA measurement buffer after kexec syscall

2021-03-04 11:37:50 +01:00

kexec_internal.h

…

kexec.c

LSM: Introduce kernel_post_load_data() hook

2020-10-05 13:37:03 +02:00

kheaders.c

…

kmod.c

…

kprobes.c

kprobes: Fix to delay the kprobes jump optimization

2021-03-04 11:38:35 +01:00

ksysfs.c

…

kthread.c

kthread: Extract KTHREAD_IS_PER_CPU

2021-02-07 15:37:17 +01:00

latencytop.c

…

Makefile

kbuild: update config_data.gz only when the content of .config is changed

2021-05-11 14:47:37 +02:00

module_signature.c

module: harden ELF info handling

2021-03-25 09:04:11 +01:00

module_signing.c

module: harden ELF info handling

2021-03-25 09:04:11 +01:00

module-internal.h

…

module.c

module: harden ELF info handling

2021-03-25 09:04:11 +01:00

notifier.c

notifier: Fix broken error handling pattern

2020-09-01 09:58:03 +02:00

nsproxy.c

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padata.c

padata: fix possible padata_works_lock deadlock

2020-09-04 17:51:55 +10:00

panic.c

panic: don't dump stack twice on warn

2020-11-14 11:26:04 -08:00

params.c

params: Replace zero-length array with flexible-array member

2020-10-29 17:22:59 -05:00

pid_namespace.c

kernel/: fix repeated words in comments

2020-10-16 11:11:19 -07:00

pid.c

exec: Transform exec_update_mutex into a rw_semaphore

2021-01-09 13:46:24 +01:00

profile.c

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ptrace.c

ptrace: Set PF_SUPERPRIV when checking capability

2020-11-17 12:53:22 -08:00

range.c

kernel.h: split out min()/max() et al. helpers

2020-10-16 11:11:19 -07:00

reboot.c

reboot: fix overflow parsing reboot cpu number

2020-11-14 11:26:03 -08:00

regset.c

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relay.c

kernel/relay.c: drop unneeded initialization

2020-10-16 11:11:22 -07:00

resource.c

kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()

2020-10-16 11:11:18 -07:00

rseq.c

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scftorture.c

scftorture: Add cond_resched() to test loop

2020-08-24 18:38:38 -07:00

scs.c

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seccomp.c

seccomp: Add missing return in non-void function

2021-03-04 11:38:32 +01:00

signal.c

ptrace: fix task_join_group_stop() for the case when current is traced

2020-11-02 12:14:19 -08:00

smp.c

smp: Fix smp_call_function_single_async prototype

2021-05-14 09:50:46 +02:00

smpboot.c

kthread: Extract KTHREAD_IS_PER_CPU

2021-02-07 15:37:17 +01:00

smpboot.h

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softirq.c

softirq: Add debug check to __raise_softirq_irqoff()

2020-09-16 15:18:56 +02:00

stackleak.c

stackleak: let stack_erasing_sysctl take a kernel pointer buffer

2020-09-19 13:13:39 -07:00

stacktrace.c

stacktrace: Remove reliable argument from arch_stack_walk() callback

2020-09-18 14:24:16 +01:00

static_call.c

static_call: Align static_call_is_init() patching condition

2021-04-07 15:00:06 +02:00

stop_machine.c

stop_machine, rcu: Mark functions as notrace

2020-10-26 12:12:27 +01:00

sys_ni.c

mm/madvise: introduce process_madvise() syscall: an external memory hinting API

2020-10-18 09:27:10 -07:00

sys.c

kernel/sys.c: fix prototype of prctl_get_tid_address()

2020-10-25 11:44:16 -07:00

sysctl-test.c

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sysctl.c

sysctl.c: fix underflow value setting risk in vm_table

2021-03-17 17:06:25 +01:00

task_work.c

task_work: cleanup notification modes

2020-10-17 15:05:30 -06:00

taskstats.c

taskstats: move specifying netlink policy back to ops

2020-10-02 19:11:12 -07:00

test_kprobes.c

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torture.c

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tracepoint.c

tracepoint: Do not fail unregistering a probe due to memory failure

2021-03-04 11:38:03 +01:00

tsacct.c

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ucount.c

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uid16.c

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uid16.h

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umh.c

usermodehelper: reset umask to default before executing user process

2020-10-06 10:31:52 -07:00

up.c

smp: Fix smp_call_function_single_async prototype

2021-05-14 09:50:46 +02:00

user_namespace.c

capabilities: require CAP_SETFCAP to map uid 0

2021-05-07 11:04:31 +02:00

user-return-notifier.c

…

user.c

…

usermode_driver.c

bpf: Fix umd memory leak in copy_process()

2021-03-30 14:32:03 +02:00

utsname_sysctl.c

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utsname.c

…

watch_queue.c

…

watchdog_hld.c

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watchdog.c

watchdog: fix barriers when printing backtraces from all CPUs

2021-05-19 10:13:00 +02:00

workqueue_internal.h

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workqueue.c

workqueue: Move the position of debug_work_activate() in __queue_work()

2021-04-14 08:42:10 +02:00